Finish for cellulosic textile materials



Feb. 24, 1959 K. B. BzER ET AL FINISH FOR CELLULOSIC TEXTILE MATERIALS Filed oct. 16, l1957 e A o .n h6 m Q/ f Y n w MU d w z O O 5 0 `5 nOu. M 25u nOu :2v m

2,875,100 Patented Fel). 24, 1959 cal Company, Midland, Mich., a corporation of Delaware Application October 416 195,7, Serial No. 690,528 16 Claims. (Cl. 117-1395) This invention relates to the finishing of yarns, threads, cords,-strings and the like and related filamentary structures and textile materials that are of artificial or synthetic cellulosic origin in order to facilitate their construction into cloth and fabric. The invention has particular reference to the sizing of warp ends of such cellulosic textile materials for subsequent weaving operations. Itl also relates to the finished cellulosic yarns and the like that are obtainable through its practice.

The cellulosic textile materials that are contemplated as being adapted `for employment in the practice of the present invention include any of the essentially or substantially pure artificially regenerated or reconstituted cellulosic materials such as those that have been obtained, for example, vfrom either the viscose, cuprammonium or analogous processes or modified synthetic cellulosic textile materials such as the conventionally available types of cellulose acetate and other cellulose esters o-f the liberforming variety, including cellulose propionate, cellulose butyrate and the4 like. The viscose rayon and acetate rayon types of so-called artificial or synthetic silk textile fibers are the most common and widely available Varieties of the cellulosic textile materials that may advantageously be utilized in the practice of the present invention.

It would be an advantage to provide an effective and relatively inexpensive means for finishing various cellulosic textile yarns andthe like, `particularly viscose rayon and acetate rayon yarns and filaments. Such a finish would be especially desirable if it could adequately protect the yarn during the course of its construction `and conversion into cloth and fabric without exerting any adverse eli'ect upon its physical or` chemical constitution. Its utility would be replete and its desirability greatly enhanced if' it were capable of temporary or fugitive application and. would not require or involve the utilization of unusual or extraordinary scouring techniques to achieve its complete removal from the cellulosic yarn or fabric constructed therefrom. It would be particularly advantageous to provide such means to size warp ends of cellulosic yarn, particularly warp ends of viscose or acetate rayon, for subsequent'weaving operations. A cellulosic yarn finished accordingly would be a most proficuous commodity. The achievement of these desiderations and cognate advantages and benefits are, therefore, amongst the principal objects and purposes of thepresent invention.

To the realization and beneficial achievement of these and related ends, cellulosic yarn of the indicated varieties, including, in particular, viscose rayon and acetate rayon, may advantageously'be finished for its construction into cloth and fabric by the application thereto or deposition thereon of a plastified film of mixed aromatic polycarboxylic acid compounds such as may be obtained from the oxidation of coal which, for convenience, are hereinafter referred to as coal acids compounds. The coal acids compounds may either be the free coal acids, the water-soluble salts, especially the alkali metal (including lithium, sodium and potassium), magnesium and ammonium salts of the coal acids or` mixturestthereof. Ad-

' of styrene and vantageously, the finishing film of the coal acids compounds maybe plastified by a solvent material for the coal acids compounds that are selected from the described group and the finish application may be accomplished with a solution of the coal acids compounds in such solvent material. Preferably, the film is plastilied with water and the coal acids compounds are applied in an aqueous` solution order to finish the cellulosic yarn. It is usually desirable and economically attractive to utilize the `free coal acids for finishing cellulosic yarn, although in` many instances and for many purposes, particularly where a less acidic finish may be required, the water-soluble coal acids salts may be used suitably. It is usually of greatest advantage to size warp ends of cellulosic yarn preparatory to weaving by application of-an aqueous solutiotior mixture of the free coal acids or their water-soluble salts or mixtures of the free coal acids and their salts to the yarn by means of conventional` slashing techniques.

Cellulosic yarn of the so-called artificial or synthetic silk variety that is finished or sized in accordance withithe present inventionwith a plastified film of coal acids compounds (which, as indicated, may be comprised of either the free coal acids, their water-soluble salts ormixtures thereof), is adequately lubricated to minimize friction and has excellent resistance to abrasion upon passage through mechanical yarn handling apparatus. This facilitates its being woven or knit into cloth or fabric without injury or operational difiiculty. In additiomthe yarn is not harmfully or objectionably influenced by either dis'- coloration or diminishment of physical properties due to the presence of the coal acids sizing finish. Besides this, a coal acids compounds finish comprised of either the free acids or their salts, is not injurious or significantly corrosive to the guides and other yarn contacting surfaces and elements in conventional yarn handling and cloth or fabric manufacturing equipment. Furthermore, cellulosic yarn that is provided with a coal acids finish may be scoured to a clean and finish-free condition by conventional techniques using the ordinarily employed detergent baths and scouring agents. The cellulosic yarn that is finished according to the invention is at least commensurate and may frequently be superior in these and other particulars to yarns finished or sized with conventional materials, such as the sodium salts of copolymers maleic acid in about equimolar proportions in the polymer molecule, and the like, similar to or identical with that which is available from the Monsanto Chemical Company under the trade-designation Stymer S. A specimen of an artificial silk cellulosic textile yarn finished in accordance with the present invention is schematically represented in Figure l of the accompanying drawing.

Any solvent substance for the coal acids compounds that is inert and non-deleterious to the cellulosic material in the yarn being sized may be employed for formulation of the applicating solution and to plastify the finishing substance. lt is, as indicated, usually most beneficial and preferred to utilize water for such purpose. However, in many cases, other solvent substances, particularly polar solvents, may be suitable, including glycerine, normally liquid glycols and polyglycols and the like, especially those having relatively high boiling characteristics. Aqueous mixtures of many polar solvents, such as water-glycol combinations, may also be found satisfactory for dissolving and plasticizing the coal acids compounds.

A sufficient quantity of the solvent should be retained in the plastified coal acids compounds film that envelops the yarn as a finish to permit it to be soft, adequately flexible or pliable and sufficiently lubricatory to achieve.

the desired function. The film should be sufficiently plastified to allow suitable and effective permeation ofthe yarn, especially when multiple filament yarns are involved,

`while remaining in a substantially continuous film phase on the surface of the yarn. ,k It should also be capable of v' ,substantially regaining its essential continuity on the sur- .,-ace after having been temporarily broken by such .dekv'formations of the yarn as bending or flaring of multiple ,iv-filament yarns which may occur in handling. Generally,

a plastified coal acids compound film that contains between about 0.5 and 10.0 percent by weight of Water, based on the weight of the film, will exhibit these desirable properties. A water content in an aqueous plastitied coal acids compound film that is in the desired range may .usually be' simply maintained by keeping the finishing film at elevated temperatures in order to more quickly achieve the desired degree of plastification in the film after application of the solution. As is apparent, the actual water content of aqueous plastified coal acids compounds films is generally dependent on the relative humidity of the atmosphere to which the finish films are exposed.

The cellulosic yarn may be finished so as to pick up or retain any desired 'quantity of the plastified coal acids compounds film as a finish. For purposes of most fabric construction, there is usually littlev benefit to be achieved when alfinish pick-up greater than about 20 percent by weight, based on the weight of the yarn is exceeded. Advantageously, the pick-up may be between about 0.5 and l percent by Weight. Oftentimes an amount of the -plastified coal acids compounds film on the yarn that is in the neighborhood of 3 percent by weight may be found suitable, especially for purposes of finishing continuous filament yarns. When yarns that have been rnechanically spun from staple lengths are being finished, it may sometimes be advantageous to apply comparatively greater quantities of the coal acids compounds film than may be best suited for filament yarns. In addition, especially when spun yarns are being finished, it may also be beneficial to employ thickening agents in the applicating solution ofthe coal acids compounds in order to facilitate i achievement of the desired finish pick-up on the yarn.

The finish application may be accomplished readily by immersing the yarn in the aqueous or other solution of coal acids compounds until the desired quantity of the coal acids compounds that are to remain in the plastiiied finishing film has been assimilated by the yarn. The usual type of operation that is involved in conventional slashing procedures using ordinary slashing or sizing mechanisms may be employed with expedience for such purposes. If

desired, however, the aqueous or other solution of the coal acids compounds may be applied to the cellulosic yarn according to other known .procedures for the application of textile finishes. Thus, as will be evident to those skilled in the art, roller or wick finish applicators and liquid jet or spray devices and techniques may also ,be employed for application of the coal acids solution.

Asmentioned, air or other types of drying, as with the assistance of heated ovens or their equivalent, such as heat lamps, after application of the solution is usually sufficient for formation of the desired film finish. Any cellulosic yarn in twisted or untwisted condition that consists of multiple or indiivdual continuous filament lengths or` is fabricated by being spun from staple lengths may advantageously be finished according to the invention.

The mixed aromatic coal acids compounds that are employed for finishing cellulosic yarn in the practice of the invention may be identical with or similar to those which may be obtained by the oxidation with gaseous oxygen, which may be contained in the air, of an aqueous alkaline slurry of a finely divided carbonaceous material selected from the group consistin'g'of coal and coke that has been obtained by the carbonization of coal at temperatures beneath about l300 F. Coal acids compounds that have been obtained by the nitric acid oxidation of suitable carbonaceous materials are also generally satisfactory. Such coals that are of the varieties known as anthracite, bituminous and lignite and other low grade coals are generally suitable for production of coal acids. Satisfactory cokes are those produced according to conventional techniques from coal at a temperature Abeneath about 1300 F. The utilization of higher coking temperatures frequently causes the cokes that are obtained to be graphitic and rendered unsuitable for conversion to coal acids compounds in satisfactory yields.

The preparation of coal acids compounds from coal may, by way of illustration, involve mixing a ground bituminous coal with a caustic alkali, such assodium hydroxide, and water using an excess of the caustic with respect to the amount that is contemplated as being required for neutralizing the coal acids compounds that are formed. Generally, an apparatus is employed that is constructed from a corrosion-resisting material of construction and that is adapted for operation under pressure. The apparatus is also equipped with an efficient mixing or agitating mechanism and with suitable heat-exchanging means. The weight ratio of the charged ingredients may,

for example, be in the proportion of about three parts by solution. This usually requires a period of time between about two and three hours. In the oxidation reaction that occurs, about half of the carbon in the coal is converted to organic acid compounds while the remainder is oxidized to carbon dioxide. Upon termination of the reaction and cooling of the reaction mass, the coal ash is filtered out o'f the alkali-neutralized coal acids solution that is obtained.

The free coal acids may then be isolated by acidifying the solution with sulfuric acid and, after filtration, recovering the Water-soluble free acids by extraction Vwith a suitable Water-immiscible solventsuch as methyl ethyl ketone, which does not dissolve in water in the presence of such salts as sodium sulfate, which is obtained in the acidified free coal acids solution. Evaporation and drying techniques vmay beV employed for subsequently isolating the free coal acids. The coal acids may thus be prepared as solid materials that are gften pulverized for subsequent handling in a powder orm.

The free coal acids products is a hygroscopic, usually yellowish, essentiallywater soluble material. Its water-soluble salts usually have similar characteristics. The free coal acids product is believed to be substantially comprised of various aromatic polycarboxylic acids. The average molecular Weight of the coal acids that are ordinarily obtained is frequently in the neighborhood of Z50-270. Their average molecular weight is seldom less than 200 or more than 300. The average equivalent weight of the coal acids is generally about seldom being less than 70 or more than 90. The free coal acids ordinarily appear to have an average of from two and one-half to five carboxylic groups per molecule with an apparent average of about three to four being common. While their exact chemical nature and constitution may be somewhat conjectural, they evidently contain considerable quantities of triand tetra-carboxylic benzene acids as well ,as aromatic acids having more complex nuclei. Frequently, for example, the

tained-in coal acids compounds prepared i111 the; described fashionhave been..1 found to consist of. methyl: tiaplithw lene, benzene,. biphenylp naphthalene,1phenanthrene', al'.- kyl! benzene (including'. toluene.) and benzophenone` nuicllci- .11V 1 1 Thev employment ofr either. the 1free coal .1 acids; or their waterfsoluble salts, orV mixtures thereof, for finishing cellulosic yarndepends to `a great extent,. as hasA been mentioned, on` thel degree of-acidity that. is. desired` in theA finish. It 1.is1. frequently more beneficial and may oftenlbe: preferred,.as: indicated, to.` employ the free coal acids, which.` generally have a.` pH near 2,` for this purpose; t .Less acidic. finishes of coalacids. compounds,` may befprovidedby utilization of the: salts or various mixtures of.the1salt's` (including partial or acid` coal acid salts) with'. the freecoatlacidssproduct.

1 UByf' way ofi' further illustration, the efiicacy of al coal acids? finishl'onL/celltilose acetate rayon-1 multiple` filament yarn1was determined inf-a1 series? of tests inrwhich a` 150 denier,l 40 filamentY nominally twisted yarn was employed. A niixed aromatic free' coal acids product was utilized that had been prepared by `tl`1e alkaline oxidation of?. coal. The coal acidsproduet had an1 averagemolecul'ar'weight of about 284 (as determined by boiling point greatly prephder-'ant propo'rtirm` of aromatic nuclei: ob-

1 elevation tests), anapparent1 equivalent weight of about 8416 and; upon analysis, was1 found to1 contain1 about 54236 preent by Weight-9 off combinedy carbong about 3.l`0 percent by weight" of combined hydrogen; about `.'52{1 percent byweight of combined'1 nitrog'eri;1 about 02116 percent? by weight of11combined1` sulfur; and11t`o1 have a carbontolhydrogen ratio-of about-l 1.46:1 with an av` eilageffunctionality 1or` number of carboxylic groups per molebuleof1abou`t 3236. The coal' acids1 finish was applied"1on`the`yarn by conventional slashing" techniques using `an aqueousvsolutio'n of thecoalv acids"` that con# tained-aboutf percent4 by `weight of dissolved solids;

resulting plstied `coal acidsfi'nished film was, with respectfto its water content, inlsubstantialiequlibrium with air at a" temperature of about 70 F.1thathad a relative humidity of aboiit 65 percent. 'Iheequilibrium condition was obtained bylconditioning the finished yarn for at least12`4` hours in anatmosphere1 ofthe indicated i character 1' subsequent` toffthe" slashing operation. For ""rplos'es` of comparison; the coal acids finished cellulose acetate yar'nwas tested' along` with acetate rayon yarn plurality of. taut; `ends-orf theiinishedgyarn samples? to the: reciprocal. jabrading. actioniof apair of1.j.oscillating knife edges that were'. opposed to one another and n `contact intabout perpendicularrelatiyedisposition with bothsides of the yarn.. The tests were; conducted on a modified version of 1an; apparatus that isv knownas a Dfuplan Cohesion` Tester (.for rayon, and raw silk) which is manufactured by Geier' & Bluhm, Inc., Troy, New York, and were performed in" ay generally analogous manner to the` equipment manufacturers recommended procedure; The:1 number. 1.01?` oscillations` o1 cycles.` required toy causel failure of the yarn size: and fraying of the yarn were observed in each of the tests. The `results1 of" the f tests.y arefgraphically `illustrated in Figure 2 of then accompanyingdrawing in" which. the fray point, as Yexpressed.itl-r1thenumber. ofA cycles: requiredl for its. accomplishment, is plotted; against. the*4 quantity of finish onctheV yarn,.expressed. inpercent by weight, based on `the weight of theyarn. The coalkacid's: finished yarn is represented by the solid data points in 'the graph while the data pointsobtained on-` the yarnlfinished with the Stymer 1S are represented by open' circles; For cons venience1 in interpretation, nvavcr'ageor mean value line 'is` drawnthrough the represented data points. As is apparent, the coal acids finish was at'` least as efiective in protecting the'` yarn1from11abrasion1as was the conventional Stymer S finish.

`Inforder to' determineth'e possible degradative effect of the"coal1acids'on1the acetate rayon yarn, two skeins of the11safr1`e yarn1 asfem'ployed in the` foregoing were sized with1 acoal acids finish using the same coal acids i111 a siniilarmethod" of application as"` are set forth above. OneofV the skeins was provided with an abnormally large amount of the finish application1 (in the neighborhood of 10-12 percent by weight, based on the weight of the yarn) while thefotlier was" provided with an amount of the size in the `neighborhood of 5 percent by weight. Two additional' skeins of thesame acetate rayon yarn1 were similarly szedfwith- Stymer .S`; 1one having an abnormally heavy application of the finish and the other a lesser quantity of finish in the commerciallyV employed range: All Vof the1 skeins were then stored.` under conditions of constant temperature and humidity (about Fa and 65 Vpercent relative humid ity) for an extended period. The breaking load and percent elongationof each of the sized yarns was deofthe'sametypethat was'finished with Stymer S. The termined at frequent intervals during the tests. The re- Stymer S was employed in a conventionallmanneracl sults are set forth in the following tabulatlon;

TABLE `1 1. `Eihzclfon,lphinstrrl properties of cellulose dcte yarn provided with various .sizing fmlfhes` y Y' Breaking Load in Grams Percentllongatlon Time iuiD-ays y H-OA v (H-syHeavy (L-s) Light (L-CA)L1ght (rr-CA) HeavyA Y Application of Applicationot Application of Application of H-S L-B L-CA Stymer S 1 Stymer S" OoalAclds Coal Acids 1 213.2 161.5 1180.6 167.31` 1 `7.3 .i `so` 18.6 13.3 i 183. 0 165.8 153.4 Averago 154.12 AverageV 1 7.3 20.4 14.7 AAverage 10.5 Average 183.2 171.6 158.8 164.81 ,170.4 1113.7 1 1 6.2 17.9 15.3 17.0f 11.9 `12.5 179.2 165.2 1167.0 162.8 5.5 17.4 19.3 14.2 163.6 160.4` 158.5 Y `164.6 112.8 17.2 17.7 1 y 14.0 178.0 164.6 175.6 Average 5170.4 Average 7.2 17.11 18.1' 5 Average `11.1 Average 1713.4` 163.2 162.8 165.3 Y `166.81612 `6.0 .17.5 15.1 17.5 1 15.2 13.5 174.4 y 159.2 5.1 16.17 18.7 113.9

cording to the manufacturers recommendation by means ofaslasher.

Several .samples 10i boththe coal acids finished and the"Styr`ner S finished acetate rayon yarn, containing variedamounts .of applied. finish, were subjected to abrasion tests in whichthe .yarn wasrun to a fray point at. which the component individual filaments i111 the yarn remained flaredaoutL or spread. apart 'whenfthe yarn was notunder.tension;y .The-.tests consisted` of subjecting a wastwashed with waterfor about lminutes at a tem-` perature between about 10,0 and F.` After the vplain water scouring,

7 the washed yarn was dried and analyzed for residual acid.V None could be found. This indicated `that the coal acids finish had been completely and readily removedby the plain water Wash. In another of the tests, similar yarn samples that have a relatively light coal acids finish applications ofabout -6 percent by weight were examined colorometrically 'for traces of finish after having been washed at a temperature of about 150 F. in a 0.25 percent aqueous solution of Triton X-l00," that contained about 0.25 percent by weight of tetrasodium pyrophosphate, and subsequently rinsed for l0 minutes in warm water and dried. Triton X'l00 type of detergent that is available under the indicated trade-designation from Rohm & Haas Company. 'Ihe samples were compared with a similarly scoured sample of unfinished yarn and also with similar samples that had been finished with the partial sodium salts ofthe free coal acids which were applied from an applicating solu tion having a pH of about'S and Stymer S. The colorometric examination consisted of wrapping the scoured yarn samples on small white plastic chips and analyzing them with a ModelNo. 75 Hunter Color and Color- Difference Meter supplied by the Henry A. Gardner- Laboratory, Inc. of Bethesda, Maryland. Thisvinstrument photometrically measures the amount of reflectance (Rd) and color (a-l-b) that lis 1 obtainable from the yarn samples. The reflectance .value is a measure of the amount of light reflected from the yarn samples in comparison to that reflected from a standardwhite tile. The color value indicates the deviation of the sample from White. `Negative afvaluesare indicative yof the presence of a'blue-green color in the sample and positive b values are indicative of the relative degree of yel low that is present. The results that were obtained are included in the following table.

TABLE z Color of various scoured cellulose acetate yarn samples Sample Rs a v b Unfinished control ggz -tl Firswstymer s'f amsn 25:1 i010 +238 Second Stymer S" finish :g2g ,ig First tree coal acids finish gg :g1g l Second tree coal `acids finish?. gg: g :3: gg Fist. gai-tial sodium salts of free coal acids gg ms Second partial sodium salts of free coal acids 19.9 -'0.3 f 2+3.8

1 The increase in yellowness of the sample some grease which inadvertently became smudged on the yarn while it was being wound on the plastic chip.

thereon.

, tures thereof with'alkali metal salts or with one another or with free coal acids'areapplied on spun yarns. Excellent Vresults analogous to the foregoing may likewise be ``obtained when viscose rayon yarns are finished and sized in accordance with the present invention or when cellulosictyarns of-theindicated varieties, either filament is an alkylaryl polyester. alcoholwas' believed to be due to i or spun, are sizedor finished with coal acids compounds fon-subsequent knitting operations. Furthermore-the coal acids compounds may also beemployed withben'efit for finishing cellulosic yarns in accordance with the present invention -when such compounds are employed in combination with other finishing or sizing materialsfor yarns of cellulosic origin thatare compatiblewith the coal acids compounds. In addition, samples of filament or other forms of acetate rayon or viscose rayon 4,yarn (for example, acetate yarn similar to that specifically described in the foregoing illustrative specification) that has been sized in accordance with thelinvention'to obtain about 3 percent (or more or less) by weight ofthe finish film on the yarn may be advantageously -employed .presently employed commercial finishes for the yarn,

including starches and oleaginous substances.

What is claimed is: v

l. Method for finishing cellulosic yarn selected from the group consisting of regenerated cellulose -aud,ber forming cellulose esters to facilitate its constructionfinto cloth and fabric which comprises depositing on.the,sur face of the yarn up to about 20percent by weight, based on the weight of the yarn, of a plastfied film of coal acids compounds selected from the group consistingqof freecoal acids and mixtures thereof; said coal acids being the water-soluble mixed aromatic polycarboxylic acids thatare the products of the oxidation of coalrand the like carbonaceous materials, which acids typically have an average molecular weight of from about 200 to 300, an average apparent equivalent weight of from about 70 to 90, and containY an average of from about 2.5 to 5 carboxylic groups per aromatic nucleus in their molecule, said film being plastified with a lsolvent for said coal acids compounds that is inert to said cellulosic yarn.

2. Method for finishing cellulosic yarn selected from the group consisting of regenerated cellulose and fiberforming cellulose esters to facilitate its construction into cloth and fabric which comprises applying to the yarn a solution of coal acids compounds selected from Athe group consisting of free coal'acids', water-soluble salts of free coal acids and mixtures thereof, said ,solutionoontaining a solvent for coal acids compoundsthatis inert to said'cellulosic yarn;` and forming therefrom upto about 20 percent by weight, based on the weight of the yarn, of a plastified coal acids film that is plastified with said Isolvent on the surface of the yarn; said coal acids being the watersolublemixed aromatic polycarboxylic acids that are the products of the oxidation of coal and the like carbonaceous materials, which acids typically have an average molecular weight of from about 200 to 300, an average apparent equivalent weight of from about 70 to 90, and contain an average of from about 2.5 to 5 carboxylic groups per aromatic nucleus in their molecule.

3. Method for finishing cellulosic yarn selected from the group consisting of regenerated cellulose and fiberforming cellulose esters to facilitate its construction into cloth and fabric which comprises applying to the yarn an aqueous solution of coal acids compounds selected from the group consisting of free coal acids, watersoluble salts of free coal acids, and mixtures thereof; and forming therefrom up to about 20 percent by weight of a water-plastified coal acids film on the surface of the yarn; said coal acids being the Awater-soluble mixedaromatic polycarboxylic acids that are the products of the oxidation of coal and the like carbonaceous materials, which acids typically 'have an average molecular equivalent weight -of from about 70 to 90, and-contain an average of from about 2.5 to carboxylic groups per aromatic nucleus in their molecule.

4. The method of claim 3, wherein between about 0.5 and percent by weight of said water-plastiiied film of said coal acids compounds is formed on the surface of the yarn.

5. The method of claim 3, wherein the aqueous applicating solution of the coal acids compounds contains between about 0.5 and 30 percent by weight of the coal acids compounds, based on the weight of the solution.

6. The method of claim 3, wherein the aqueous applicating solution of the coal acids compounds contains between about 2 and 8 percent by weight of the coal acids compounds, based on the weight of the solution.

7. The method of claim 3 and including the intermediate step of drying the applied aqueous solution of said coal acids compounds to about moisture equilibrium with the surrounding atmosphere` to form the plastied film thereof on the surface of the yarn.

8. The method of claim 3, wherein the yarn is a multiple lament yarn.

9. Cellulosic textile yarn selected from the group consisting of regenerated cellulose and fiber-forming cellulose esters provided with up to about 20 percent by weight, based on the weight of the yarn, of a iinish comprised of a plastified film of coal acids compounds selected from the group consisting of free coal acids, water-soluble salts of free coal acids, and mixtures thereof; said coal acids being the water-soluble mixed aromatic polycarboxylic acids that are the products of the oxidation of coal and the like carbonaceous materials, which acids typically'have an average molecular weight of from about 200 to 300, an average apparent equivalent weight of from about 70 to 90, and contain an average of from about 2.5 to 5 carboxylic groups per aromatic nucleus in their molecule, said film being plastied with a solvent for said coal acids compounds that is inert to said cellulosic yarn.

10. Cellulosic textile yarn selected from the group consisting of regenerated cellulose and liber-forming cellulose esters provided with up to about 20 percent by weight, based on the weight of the yarn, of a finish comprised of a water `plastified film of coal acids compounds selected from the group consisting of free coal acids, water soluble salts of free coal acids, and mixtures thereof; said coal acids being the water-soluble mixed aromatic polycarboxylic acids that are the products of the oxidation of coal and the like carbonaceous materials, which acids typically have an average molecular weight of from about 200 to 300, an average apparent equivalent weight of from about to 9 0, and contain an average of from about 2.5 to 5 carboxylic groups per aromatic nucleus in their molecule.

11. Cellulosic yarn finished in accordance with claim 10 with between about 0.5 and 10 percent by weight of the water plastitied coal acids compound film, based on the weight of the yarn.

12. Cellulosic yarn finished in accordance with claim 10, wherein the water-plastied film of said coal acids compounds is substantially in moisture equilibrium with the surrounding atmosphere.

13. Multiple filament yarn finished according to claim 9.

14. Sized warp ends of yarn in accordance with claim 9.

15. Viscose rayon yarn finished according to claim 9.

16. Cellulose acetate rayon yarn linished according to claim 9.

References Cited in the file of this patent UNITED STATES PATENTS 2,199,989 Dickey et al May 7, 1940 2,292,211 Dickey Aug. 4, 1942 2,779,684 Alles Jan. 29, 1957 2,803,607 Stroh Aug. 20, 1957 2,808,340 Learn Oct. 1, 1957 

1. METHOD FOR FINISHING CELLULOSIC YARN SELECTED FROM THE GROUP CONSISTING OF REGENERATED CELLULOSE AND FIBREFORMING CELLULOSE ESTERS TO FACILITATE ITS CONSTRUCTION INTO CLOTH AND FABRIC WHICH COMPRISES DEPOSITION ON THE SURFACE OF THE YARN UP TO ABOUT 20 PERCENT BY WEIGHT, BASED ON THE WEIGHT OF THE YARN, OF A PLASTIFIED FILM OF COAL ACIDS COMPOUNDS SELECTED FROM THE GROUP CONSISTING OF FREE COAL ACIDS AND MIXTURES THEREOF; SAID COAL ACIDS BEING THE WATER-SOLUBLE MIXED AROMATIC POLYCARBOXYLIC ACIDS THAT ARE THE PRODUCTS OF THE OXIDATION OF COAL AND THE LIKE CARBONACEOUS MATERIALS, WHICH ACIDS TYPICALLY HAVE AN AVERAGE MOLECULAR WEIGHT OF FROM ABOUT 200 TO 300, AN AVERAGE APPARENT EQUIVALENT WEIGHT OF FROM ABOUT 70 TO 90 AND CONTAIN AN AVERAGE OF FROM ABOUT 2.5 TO 5 CARBOXYLIC GROUPS PER AROMATIC NUCLEUS IN THEIR MOLECULE, SAID FILM BEING PLASTIFIED WITH A SOLVENT FOR SAID COAL ACIDS COMPOUNDS THAT IS INERT TO SAID CELLULOSIC YARN. 